Relationship between plasma melatonin levels and the efficacy of selective serotonin reuptake inhibitors treatment on premature ejaculation.

Objectives: To examine the relationship between premature ejaculation and plasma melatonin levels, and assess the efficacy of selective serotonin reuptake inhibitors in treating premature ejaculation.

Methods: A total of 60 men with lifelong premature ejaculation and 40 healthy male controls were included in the present study. For each participant, a medical history was obtained, a physical examination was carried out, and intravaginal ejaculation latency time and melatonin levels were measured. Premature ejaculation patients were randomly categorized into three treatment groups: group 1 received fluoxetine (20 mg/day), group 2 received paroxetine (20 mg/day) and group 3 received sertraline (50 mg/day).

Results: The mean baseline plasma melatonin levels in men with premature ejaculation were significantly lower than in the healthy controls (5.34 vs 14.84 pg/mL). After 4 weeks of treatment, the mean intravaginal ejaculation latency time scores for all of the premature ejaculation treatment groups showed a significant improvement from the baseline values. The plasma melatonin levels were also significantly increased (P < 0.05) from baseline (5.34 pg/mL) to 9.50 pg/mL, 10.24 pg/mL or 13.30 pg/mL for groups 1, 2 and 3, respectively.

Conclusions: Our findings show that premature ejaculation is associated with decreased plasma melatonin levels. After treatment with selective serotonin reuptake inhibitors, an increased plasma melatonin level can retard ejaculation, presumably by both central and peripheral mechanisms. This is the first study to evaluate the possible role of serotoninergic interactions on the melatoninergic system in premature ejaculation.